1. Field of the Invention
This invention relates generally to an engine-driven model toy, and more particularly to an engine-driven model toy having an engine; an electric motor, which is connected to the engine and has two-fold functions of an electric motor at the start of the engine and a dynamo during the continuous operation of the engine; a power source battery; a transmission mechanism capable of changing over the engine/motor speed ratio at predetermined values in accordance wth the starting and continuous operation modes of the engine; and a switching mechanism capable of switching the battery connection from series to parallel connection or vice versa in accordance with the operating modes of the motor.
2. Description of the Prior Art
In general, an engine-driven model toy, such as a model airplane, is equipped on-board with an engine as its power plant, a control unit for starting the engine or controlling the engine and the airframe, and a rechargeable Ni-Cd battery, etc. as a power source for operating them.
In the conventional type of model airplane, the engine has been started by turning the propeller by hand. This has been very cumbersome and apt to involve the danger of hand injury by the revolving propeller. To cope with this, an external engine driving means (such as an engine starter) is often provided separately to start the propeller. This, however, requires separate provision of the driving means, increasing the overall cost of the model airplane. More recently, there is an increasing tendency toward equipping onboard the model airplane an engine starter motor which is connected to the engine drive shaft via a reduction train such as gears with clutches. In this case, however, the motor becomes useless once the engine has been started, causing a loss in the engine output due to the increased weight of the airplane, though it gives no direct load to the engine as it is disengaged from the engine by the clutch. Moreover, the battery, which has been consumed for the start of the engine, will have to be charged by a separate charger as occasion demands.
On actual motorcycles, a motor for starting the engine and a generator for charging the battery are often equipped onboard separately. However, this cannot be applied to model toys because of increases in both equipment cost and weight. Particularly, provision of a generator for charging the battery in a model airplane would increase the output/weight ratio, adversely affecting the flight performance of the airplane.